Most methods of remote mining in bedded mineral deposits such as coal seams employ a mining machine that advances parallel mine openings some distance from the seam exposure on the surface leaving supporting pillars between the openings. The excavated mineral is hauled to the surface, in some instances by a remotely operated Load-Haul-Damp vehicle or LHD. For example LHD haulage assisted by a winch is described in U.S. Pat. No. 5,582,465 to Mraz.
The remote operation of LHD using commonly available remote controls is feasible. However, in order to achieve efficient LHD haulage to a desirable distance such as 1,000 feet or more, the speed of haulage must be considerable. Typically, the average speed of LHD haulage must be greater than 400 feet per minute. Often in remote mining methods the LHD vehicle has to operate within confined mine openings, making it difficult to steer the LHD remotely without collisions with pillar walls, and thus disrupting the haulage, reducing the haulage rate and possibly causing damage to the equipment. Therefore, it would be desirable to obtain a method of guidance that would assure efficient guiding of the LHD during the remote operation.
Both the LHD and the mining machine may require services such as power, control, water and compressed air. Service lines which supply these services may include ropes, cables, electrical cables, and hoses, and are usually located in the mine opening where they may be damaged if they lay in the path of the LHD. Where the mine floor is soft, repeated trips of the LHD to the mining face and back may cause depressions in the mine floor. Such depressions may cause the service lines to slide into them and interfere with the path of the LHD. It would be therefore desirable to prevent depressions resulting from LHD haulage in the mine floor to avoid interference between the LHD and service lines, and also provide a navigable path for the LHD.
Most of the currently available LHD'S, such as shuttlecars, are powered electrically and carry a cable winder for the power cable or service line, which is unwound as the LHD advances into the face and wound in as it retreats. The LHD power cable is frequently referred to as a trailing cable. The capacity of LHD cable winders is currently limited to about 850 feet of power cable, which limits the depth of remote mining. The present practice with manually operated LHD's is to arrange a so called holdback, where the end of the LHD cable is connected to power at about half the distance of haulage. Thus the LHD can wind the cable in, up to the position of the holdback, and unwind it beyond that point, which practice can effectively double the distance of haulage. It would be therefore desirable to advance a remote cable holdback along the mine opening.
Where haulage for remotely operated mining machine is provided by a conveyor, service lines can be carried on the structure of the conveyor. This is not possible with LHD haulage. As well, to position several service line winders on a remotely operated mining machine is not practical, particularly if the depth of mining is considerable. It is also not desirable for the mining machine to drag the service lines along while it is advancing, as their considerable weight would prevent the mining machine from efficient excavation. Therefore, it would be desirable to advance the service lines as well as the above-mentioned holdback during the remote mining operation without impeding the advancement of the mining machine.